1. Volume LossAccording to Nexxus research, you’re born with 1,110 hair follicles per square centimeter on your scalp. But by the time you’re 25, this number drops to 600, then between the ages of 30 to 50, it dips again to just 250 to 300. Combine this decreasing density with narrower strands, and you’ve got limp locks.
Anti-ager: Give lifeless hair instant oomph with a thickening mousse that contains styling polymers (check the label for “polymer technology” or ingredients ending with –polymer), such as Nioxin Volumizing Reflectives Bodying Foam ($16; nioxin.com for salon retailers). These large molecules wrap around each individual hair, plumping up its diameter. To ensure that you’re coating the entire strand and not just hitting your roots, squirt is out in a straight line across your palm, Mancuso says. “Then use that hand to press the mousse into the hair and glide it down the hair shaft.”

2. BreakageMancuso isn’t exaggerating when he says everything causes breakage. “Dehydration due to sun exposure and heat styling, and abrasions from clips, ponytail holders, aggressive brushing, and chemical processes all make hair snap more easily.”
Anti-ager: The key to preventing breakage is getting moisture inside the hair, says Mancuso, who suggests a product that contains glycerin, a hydrator typically found in skincare creams. It penetrates strands, making them flexible enough to withstand styling without breaking, yet not so ultra-soft that they fall flat. Apply something like Nexxus Youth Renewal Elixir ($18; cvs.com) to wet hair to help your comb glide through knots easier, Mancuso says.
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3. DrynessWith age, your scalp produces less essential fatty acids and lipids, your hair’s natural hydrators. Your strands are also more porous thanks to years of damage, so moisture escapes more easily.
Anti-ager: Conditioner isn’t only for in the shower. “Rub it between your palms and swipe it on the ends of your hair after it’s dry and styled,” says Jet Rhys, a San Diego-based hairstylist. If you worry this may weigh down your fine strands, consider a dry conditioner to make hair look smoother and shinier while delivering a major hydration boost to parched tresses. Look for one that contains natural moisturizing oils, such as Oribe Soft Dry Conditioner Spray ($35; oribe.com), which has argan oil.

4. Less shine“Shine is about light reflection,” Mancuso says. “When the hair’s surface becomes dry and porous, there is less reflection coming off each strand.” Combing, styling, and washing only heighten the dullness by wearing away your locks’ outer layer.
Anti-ager: Instant shine is as simple as brushing your mane. A boar bristle brush, such as Olivia Garden Healthy Hair Eco-Friendly Bamboo Professional Ionic Combo Paddle Brush ($14; ulta.com), pulls the scalp’s oils through to the ends, leaving a smoother, more polished look. Now you know why all the pros use these brushes.

5. RoughnessAnother thing to blame your hormones for: how your once-silky strands now feel a bit more like a Brillo pad. Hormonal fluctuations that occur with age can lead to a change in hair’s texture, Rhys says, and this is compounded by heat and chemical damage.
Anti-ager: “Keratin protein treatments are like Xanax for your hair,” Rhys says. “They completely smooth out your texture.” In-salon treatments, during which the protein is applied to hair and then sealed in with a flatiron, can cost upwards of $300 with results that last for several months. But Rhys says you’ll also see benefits from using keratin-infused at-home products. Look for one with hydrolyzed keratin or try Organix Brazilian Keratin Therapy Hydrating Keratin Masque ($8; ulta.com), a smoothing treatment meant to be used once or twice a week.

6. BrittlenessAlthough brittle hair tends to be lumped together with dry hair, they’re not necessarily one in the same, Mancuso says. “Dry hair is not always brittle and breaking. It can still be strong; it simply lacks moisture.” Brittle hair, however, is dry and weak. “It’s over-colored, damaged, and depleted of moisture,” Rhys says.
Anti-ager: Fortify your weakened hair shaft with a protein-rich treatment that contains amino acids or wheat proteins, which will encapsulate each strand, filling in thin and weak spots. Alterna Haircare Caviar Repair Rx Micro-Bead Fill & Fix Treatment Masque ($35; alternahaircare.com) can be used daily or, for more intensive treatment, a few times a week.

7. UnrulinessAdd up all of the damage previously mentioned, and it’s no wonder you spend five to 10 minutes in the morning trying to get one section of hair to play nicely with the rest. “Unruly hair is really just uneven texture that you start to experience with age,” Mancuso says. “The structure itself is unable to lay flat.”
Anti-ager: “Just like a face primer smooths out all the tiny lines and pores in your skin, a hair primer fills in the cracks in your hair and evens out its porosity so you can style with ease,” Rhys explains. To really lock in your style, look for a primer that contains a humidity-blocker such as silicone. As an alternative, Living Proof Prime Style Extender ($20; livingproof.com) uses OFPMA, the brand’s trademark molecule that shields strands from moisture.

8. Loss of color vibrancyYep, you’re losing it—your hair color, that is. “As your hair’s structure thins out with age, there’s less space for color to get into—and adhere to—each hair strand,” Mancuso says. This happens in particular at the ends and causes your shade to fade faster.
Anti-ager: Washing will shorten your dye job’s lifespan, so skip at least one day between sudsing sessions and when you do cleanse, be gentle, Mancuso says. “I’ve done an experiment where I’ve washed one side of my hair more aggressively than the other, and you could see, almost immediately, that there was less color left on that side.” Using a mild shampoo designed for color-treated hair, such as Color Wow Color Security Shampoo ($22 for 250ml; colorwowhair.com), lightly massage your scalp with your fingertips, then pull the suds down through the length of your hair. On no-wash days, zap oily roots with a translucent dry shampoo.
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You religiously use eye cream, cover up unsightly brown spots, and apply sunscreen-yet people still often misjudge you for being five (or more!) years older. What gives?

No matter what your skin looks like, your hair may be adding years to your appearance. "Over time, our hair follicles shrink, producing a thinner, more brittle and unruly strand," says Kevin Mancuso, Nexxus creative director, who developed its Youth Renewal line to help combat the following eight signs of aging hair. Battle them yourself with these expert tips and products, and bring back your youthful looks.